UDC 628.35
DOI 10.35776/VST.2023.05.06

Нездойминов В. И., Рожков В. С., Zavorotnyi Dmitrii, Chernyshev Valentin, Vasil’eva Iuliia

Municipal wastewater treatment systems based on airlift bioreactors

Summary

The aspects of municipal wastewater biological treatment with activated sludge with the cultivation of phosphorus-accumulating microorganisms and simultaneous nitri-denitrification are considered. Improved schemes for the biological removal of organic pollutants, nitrogen and phosphorus compounds based on airlift bioreactors (BOSEB technology) are presented. The main results of pilot studies are submitted that acknowledge the effectiveness of the proposed technology in the treatment of municipal wastewater. The features of the operation of an activated sludge blanket type tank built into an airlift bioreactor have been studied. It has been experimentally established that during the operation of the sludge blanket tank, either the presence or absence of phosphorus-accumulating microorganisms in the activated sludge biocenosis does not affect the efficiency of removing suspended solids. Empirical dependences have been obtained for the calculation of the facilities for sludge separation in a self-renewing activated sludge blanket. It has been established that the main controlled parameter of the biological treatment process is the dissolved oxygen concentration in the saturation zone (upper part of the airlift bioreactor), which should be in the range of 1.6–2.4 g/m³. An economic evaluation of the effectiveness of the proposed solutions was carried out in comparison with the SBR process. The advantages of the BOSEB technology are presented in relation to the schemes of enhanced biological removal of phosphorus accepted in the Russian Federation and abroad.

Key words

biological treatment , activated sludge , airlift bioreactor , flock blanket clarification